A popular form of conventional irrigation system is the so-called central pivot system which employs a main distribution pipe mounted on a series of wheeled carriages for rotation about a central pivot point. The main distribution pipe includes a series of sprinkler heads arranged along the length thereof which spray water onto the crops as the pipe is rotated and thus provide spray coverage over the entire area traversed by the pipe. A typical system of this type is described in more detail below.
One disadvantage of such a system is that the spray is projected into the atmosphere and hence loses significant effectiveness due to evaporation. It will be appreciated that this can be a substantial problem over an extended period of time particularly where operations take place in very hot weather.
As explained below, the present invention in part concerns the provision of elongate flexible hoses which extend downwardly from the main distribution pipe to the ground and which thus releases the water at ground level. Examples of broadly similar systems are disclosed in U.S. Pat. Nos. 2,249,130 (Gunther) and 3,643,442 (Houston). The Gunther patent discloses an irrigation machine wherein lengths of flexible hoses depend from a substantially horizontal delivery pipe down to the ground so as to drag in ditches between the row crops. The Houston patent discloses an irrigating machine wherein elongated, generally flexible conduits or hoses extend downwardly from auxiliary conduits so as to discharge water directly into slots in the soil provided for this purpose.